Glow plug wiring help needed

Hi Guys,

I was fortunate to get a good deal on a L35, It only has a couple of issues. The main one is electrical. First problem was a faulty alternator, after reading here I ordered a replacement from Pats small engines.

I think what caused the Alt to fail is the glow plug controls. Most of the time the glow plug light (and plugs too) stays on all the time. I think this has caused the alt to run overloaded all the time and damaged the alternator.
Today the glow plugs didn't come on untill I pulled the dash and knocked the relays a bit, now it seems to stay on all the time again.

From searching here it seems there must be a timer that is supposed to shut the glow pulgs off.
I am looking for the location of that control. It looks like there is also a Glow plug relay.
Does anyone have the wiring diagram for these and the relay/timer location?

I just picked this up this week so I don't have a manual yet-Is there any online manuals?

Once I get the information I will see just what is wrong and figuire out if I will replace the timer or just rewire it to a momentary switch I will manually use to heat up the glow pulgs thru a relay.

Re: Glow plug wiring help needed

You may want to bypass the relay and timer and make your own set-up to manually use the glow plugs only as needed. I have done this a few times. Use a heavy relay/solenoid (the existing one may work, or a new 80-100 amp rated relay) a normally off momentary contact switch and wire it to the solenoid/relay. This allows you to control how much you glow plug and when. I found it works much better than any automated system.

Re: Glow plug wiring help needed

Exactly what I was thinking atgreene,
I've got an account at Grainger so I can pick up a weather proof switch and relay if I need one.
What I would like is to have the wiring diagram and timer location so I can rewire without tracing all the wires out behing the dash.

Re: Glow plug wiring help needed

On the Grand L's (similar - maybe identical glow plug control) the starter switch is turned until the glow plug indicator comes on and then later goes off, then the switch is turned further to start.

The parts list for the L3600 shows a timer T0070-31410 ($72) and a controller 16415-65660 ($62) These two are mounted back-to-back to the glow plug relay 16415-65600 ($26). All three pieces are mounted with 2 bolts inside the body behind the dash panel on the right side. The coolant temperature sender on the engine might be the problem - 16415-83040 ($23).

Depending on what's defective, a simple glowplug/starter switch without any relays or timers might be a cheaper fix. The older kubota models used a simple 3-position switch to send power to the glow plugs and/or the starter. The L345 switch is 37150-32200 ($35) plus knob 37150-32210 ($5) - It is wired direct to the glow plugs in one position and in the other it powers the starter circuit too. (On these models the glow plugs also get power whenever the starter runs)

Re: Glow plug wiring help needed

Re: Glow plug wiring help needed

Just a follow up to say thanks for you guys help. The glow plug controller was faulty. I decided I would rather have a toggle switch to control the glow plugs with rather than a new controller.
I picked up a 3 position toggle switch (one position is momentary) DPDT plus a weather cover ($17 total) and with the help of KennyV's wiring diagram wired it in a Auto-Off-Hand configuiration.
Auto- leaves all in original condition
Off- drops power to the glow plug control
Hand- (momentary) drops power to the glow plug control and completes
ground circuit to glow plug relay to operate glow plugs

Works great and someday when I pick up a new controller I can just change that out and it will work normally if I want.